Chain construction



July 10, 1928. 1,676,863

' R. s. KELSO CHAIN CONSTRUCTION Filed Dec. 1925 i I jwwntom Patented July 10, 1928;

UNITED: stares" g ars-s63 9A g; v

RALPH s. KnLso,.oF ROCKFORD, ILLINOIS, assrenon'ro'rn-nn snwri rq' vracnrnncom- I IPANY, or ROCKFORD, rumors, A CORPORATION or rumors,

. I CHAIN CONSTRUCTION.

Application filed December with sewing machines for transmitting pow-' or from the needle bar drive shaft to the loop taker shaft.

iiu important object of the'invcntionis-to provide a chain the individual links of which are substantially duplicates o't each other and adapted to be readily assembled without the use of special tools.

vice of the above mentionedcharacterwherein the ends of the lir 's are formed conical in shape, the apexes of the conical portions be- .ing arranged substantially. in contact witheach other in end to end relation to permit the similarly formed ends of the next adjacent link to be passed thereover to assemble the links into a completed chain.

A still further object is to provide a chain of the above mentioned character which is adapted to pass about sprocket wheels secured to parallel shafts, alternatev linksof the chain being curvedlongitudinally to conform somewhat to the curvature of the sprockets'to form a better contact between the chain and sprockets.

A still further object is to provide a novel" form of chain structure adapted to provide positive drive means between the needle bar operating shaft and loop taker shaft of a sewing machine.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the drawings I have shown one embodiment of the invention. In this showing:

Figure l is a side elevation of a sewing machine, parts being broken away,

Figure 2 is a detail sectional view through the sprockets about which the chain passes, the chain being shown in elevation,

Figure 3 is a detail sectional view through one of the sprockets, and,

Figure 4 is a detail view of a pair of chain links.

Referring to the drawings, the numeral 10 designates the bed plate of a sewing ma-- chine having the usual. head 11 arranged thereabove to support the upper driving mechanism of the machine. The head is provided with the usual depending reciprocating needle bar 12 adapted to be operated through suitable mechanism from a rotating still further oo ect is to provide de..'

a, 1925. Serial No. 73,066.

needle bar. operating" shaft provided with the usual hand wheel 14. The shaft 13 is adapted to operatein the bcaring'slfi carried by the head of i'llO'lIltlClrlI1Q flBQIlGdtl'l thebcd'" plate, the machine. is providedwith a rotating loop taker 16. adapted to be operated by a rotatable shaft 1'? supported in bearings 18; The"shaft- 13 provided wiiha sprocket 19 shown in detail in Figures 2 and 3 of the drawing. The'sprocketis.adapted to be se-- cured to the shaft 1.3 to rotatetherewith by means of a set screw 20; or other fastening device. The 711861 191l pl OVl(letl.Wlth a substantiallycylindrical .outcrrface 21 provided centrally thereof. I-withyan annular groove QZhaving sprocket teeth project ing outwardly. therefrom. These sprocket teeth are fOl'llflQtl integralwith the wheel 19 and proj ect outwardly beyond; the outer face 21 shown in Figure 2. A similar sprocket wheel 24 is secured to the .shaft- 17 as shown n Figure 2, and this sprocket is similarly provided with'an outer substantially cylindrical surface 25 having an annular" groove 26 arranged substantially centrally thereof. Sprocket teeth 27 similar to the teeth 23' project outwardly from within the groove 26. The teethQT are spaced over a distance substantially equal to the teeth 23. The nu neral 28 designates a drive chain as a whole comprising links 29 and 30. The links 29 are adapted to pass about the sprocket wheels at right angles to the surfaces thereof, while the links 30 are adapted tolie against the outer surface of the sprocket wheels. The links 29 and 30 may be formed as duplicates of the same length, or the links 29 may be formed relatively short-to bringthe adjacent ends of the links 30 passing therethrough close to each other. The links 30 are preferably ofa length sufficient to permit tne teeth. 23 to pass between the ends of the links 29 a will be obvious. In practice I prefer to form the links 30 on an arc of a circle whereby they will lie more flatly loo against the outer surfaces of the spro-cket wheels. The increased surfaces presented between the links 30 and the surface; of the sprocket wheel formed by curving the links 30 materially reduce the wear on the links 30. Referring in detail to Figure l, it will be noted that each link of the chain be formed of circular wire and thiswire is preferably made of steel.- Each link is formed with parallel sides and curved ends as shown, and the "ends ofthe material forming'the link preferably terminate centrally of one side thereof. The ends are formed substantially as cones as indicated at 31, and

the apexies' of the cones are arranged substantially' in contact with each other in end to end relation. The angle of thecone may be 90 or slightly less, for a purpose to be described. a 1

The operation of thedevice is as follows:

7 The links of the chain are assembled by placing two links in edge to edge relation with the apexes of the conical ends of the links-in registration with eachother whereby one link may be slipped into the other one and moved to the solid line position shown in Figure 4. The initiallinking position is indicated in dotted lines and it will be apparent that if the angles of the conical portions are 90 or less, successive links easily may be assembled. Whencurved links 30 are employed, it will be apparent-that alternate links of this character are assembled in forming the complete chain. After the chain has been completelyassembled, it is placed.

in posit-ionon the sprockets 19 and 24', as will be understood. The shaft 13 then may be revolved by any suitable means such as an electric motor (not shown) to reciprocatethe needle bar in the usual manner. Motion will be transmitted to the shaft 17 by virtue of the chain described, any suitable form of revolving loop taker being employed,

It is to be understood that the form of my v invention herewith shown and described is to; be taken as a preferred example of the same and that various changes in the shape,

sif/Le and arrangementof parts may be 'resorted to without departing from the spirit of the invention or the scope of the subjoined stantially conical portions the ape es of i which substantially coincide, said conical portions being substantially coaxial and having apexangles notexceeding 90, each-link of the chain being of such length that theadjacent ends of the links connected thereto are spaced a material distance apart.

In testimony whereof I affix my signature.

RALPH S. KELSO. 

